Convertible chair



Aug. 11, 1942. v DAV|$ 2,292,618

CONVERTIBLE CHAIR Filed July 17, 1940 F INVENTOR.

Mermo H. Davis w Qttqs.

Patented Aug. 11, 1942 UNITED STATES PATENT OFFICE CONVERTIBLE CHAIR Menno H. Davis, Detroit, Mich. Application my 17, 1940, Serial No. 346,051.

6 Claims.

It is the object of the invention to obtain a construction of chair which normally has the ap- Figure 1 is a sectional side elevation of my.

improved chair with the seat in its normal lowered position;

Figure 2 is a similar view showing the seat raised;

Figure 3 is a bottom plan view of the seat frame and seat raising and lowering mechanism;

Figure 4 is a transverse section on line 4-4 of Figure 3 with the seat in raised position;

Figure 5 is a section on line 5-5 of Figure 1, showing the seat in lowered position.

My improved chair may be of conventional general construction including the rear legs A extended upward to form the back B, the forward legs 0 and a seat frame connecting said legs, including the side rails D and D, front rail E, and rear rail F. G is the seat resting on the seat frame and projecting slightly beyond the same at front and sides. This may be of any suitable construction, but is represented merely as a flat board. The construction as thus far described is an ordinary dining chair and may vary in contour lines to correspond to the particular type of furniture to which it belongs.

To convert this chair into a high chair the seat G is separable from the seat frame, but normally rests thereon. Arranged within the seat frame and concealed by the rails thereof is a seat raising and lowering mechanism constructed as follows.

The seat G has depending therefrom the brackets H shown as formed of parallel strips secured at their upper edges to the seat bottom. I are strips arranged parallel to and preferably outside of the strips H, but secured to the seat frame. Between the strips H and I are arranged a plurality of crank arms J each having a portion extending in a vertical plane and laterally extending pivot pin portions J and J at the opposite ends thereof which engage corresponding pivot bearings in the strips I and H. As shown there are four of these cranks arranged in front and rear pairs adjacent to opposite sides of the seat frame. K is a cross bar connecting the strips H, and L is a spring having one end connected to the bar K and its opposite end connected to the rear rail F. The parts are normally in the position shown in Figures 1 and 5,

where the seat G rests upon the rails of the seat frame and also on the strips I. The cranks J are arranged in the space between the strips H and I and extend downward from the pivot portion J to the pivot portion J The tension of the spring L which draws the seat G rearward normally holds the parts in this position. When it is desired to raise the seat it is first drawn forward against the tension of the spring L. This will cause all of the crank arms J which are parallel to each other to first swing forward and then upward until they have completed substantially a half revolution. The spring L will then draw the seat rearward until its rear edge contacts with the back B. To maintain stability in this position the cranks J swing somewhat to the rear of their upper dead centers so as to incline slightly rearward, as shown in Figure 2. Thus, the weight on the seat will tend to hold it in this position. To permit the adjustment just described, the seat G when in its lowered position does not extend completely to the rear rail F, but is supplemented by a strip M permanently secured to the seat frame. This strip extends somewhat forward of the back so that the seat G in its upper position is slightly in rear of its lower position and the cranks J assume a rearwardly inclined position, shown in Figure 2. To avoid danger of marring the back when the seat is in raised position, buttons N are secured to the opposite sides of the back and form stops against which the rear edge of the seat contacts. The fact that the cranks J are individual and separate from each other, facilitates assembly of the parts, and also permits a slight relative angular movement, which insures that the seat will always form full contact both with the back in raised position and with the strip M in lowered position.

What I claim as my invention is:

1. In a convertible chair, the combination with a seat frame and back rising therefrom, of a seat normally resting on said frame, and a connection between seat and frame including a depending member on said seat and a plurality of parallel crank arms concealed within the frame having their opposite ends pivotally secured respectively to said depending member and frame, said arms normally extending downward from their pivotal attachment to the frame and adapted to be swung forward and upward through an angle of substantially to raise the seat and bring its rear edge into contact with said back, said seat being substantially in vertical alignment in its lowered and raised positions.

2. In a convertible chair, the combination with a seat frame and a back rising therefrom, of a seat normally resting on said frame, and a connection between said seat and frame including a depending member on said seat and a plurality of parallel crank arms concealed within the frame having their opposite ends pivotally secured respectively to said depending member and frame, said arms normally extending downward from their pivotal attachment to the frame and adapted to be swung forward and upward through an angle of substantially 180 to raise the seat and bring its rear edge into contact with said back, said crank arms in raised position inclining slightly to the rear to afford stable support for the seat but holding the same substantially in vertical alignment with its position when lowered.

3. In a convertible chair, the combination with a seat frame and a back rising therefrom, of a seat normally restin on said frame, and a connection between said seat and frame including a depending member on said seat and a plurality of parallel crank arms concealed within the frame having their opposite ends pivotally secured respectively to said depending member and frame, said arms normally extending downward from their pivotal attachment to the frame and adapted to be swung forward and upward through an angle of substantially 180 to raise the seat and bring its rear edge into contact with said back, said crank arms in raised position inclining slightly to the rear to afford stable support for the seat but holding the same substantially in vertical alignment with its position when lowered, and resiliently yieldable means for drawing said seat rearward in both its raised and lowered positions.

4. In a convertible chair, the combination with a seat frame and a back rising therefrom, of a seat normally resting on said frame, and raising and lowering means for said seat concealed within said frame comprising brackets of substantial depth depending from said seat, parallel crank arms pivotally attached at one end to said brackets and at the opposite end to said seat frame, whereby said crank arms normally extend downward from the seat frame pivot to the bracket pivot and are adapted to swing forward and upward through an angle of substantially 180 to raise the seat to a position where its rear edge contacts with said back but substantially in vertical alignment with its position when lowered.

5. In a convertible chair, the combination with a seat frame and a back rising therefrom, of a seat normally resting on said frame and raising and lowerin means for said seat concealed within said frame comprising parallel spaced strips attached respectively to the seat and frame and depending therefrom, parallel crank arms arranged between said strips having laterally oppositely extending crank pins at their opposite ends pivotally engaging bearings in the respective strips, said crank arms in one position retaining said seat in contact with said frame and adapted when swung forward and upward through slightly more than 180 to raise said seat and contact its rear edge with said back, said seat being substantially in vertical alignment in its lowered and raised positions.

6. In a convertible chair, the combination with a seat frame and a back rising therefrom, of a seat normally resting on said frame including a movable portion and a stationary portion in rear thereof, the latter extending slightly forward of said back, and means for raising and lowering said seat normally concealed within said frame comprising parallel spaced strips'secured respectively to the seat and frame and depending therefrom, parallel crank arms arranged between said strips and having oppositely extending crank pins at their opposite ends engaging pivot bearings in the respective strips, said crank arms holding said movable portion of said seat with its rear edge against the stationary portion while resting on said seat frame and adapted when swung forward, upward and rearward through slightly more than 180 to raise said seat and contact its rear edge with said back.

MENNO H. DAVIS. 

